fix: #3615522 Fix broken settings menu link and domain link URLs

The settings menu link declared its parent as domain.admins, which does not exist, so the link never appeared under the Domain administration menu. The correct parent plugin ID provided by the domain module is domain.admin.

The dropdown links also used DomainInterface::getRawPath(), which returns the unprocessed path pattern. getPath() returns the resolved domain URL, which is what the toolbar links need.

Closes #3615522